Lifesaver Bottle Ultra Filtration Water Bottle Replacement Carbon Inserts (4-pk) Activated Carbon filters made of high specification activated Carbon block Improves palatability of water by removing chlorine, taste and odor Reduces turbidity of glacial, cloudy or muddy water 4 pack will filter 1,000 liters of water before replacement is required Fits the LIFESAVER 4000Uf and 6000Uf bottle Lifesaver activated carbon inserts Its weight:0.1 pounds; height:0.3 inches; length:3.9 inches; width:3.1 inches Replace every 250 liters